Lamp starter and maintenance device



April 1943- w. c. HALL, JR ETAL 2,317,602

LAMP STARTER AND MAINTENANCE DEVICE Filed Sept. 19, 1941 MZ/AAAAAAAAVWM A1 //4 1 jllllllll \L- I l I v I u v /9 A T A A A A A [/VVEA/TDES EVERETTL. LEGE77E 5 Mun/v0 C.HA1.L,JE.

Patented Apr; '27, 1943 LAMP STARTER AND MAINTENANCE DEVICE Willard 0. Hall, Jr.,.and Everett L. Le Gette, Los Angeles, Calif., assignors to Alfred P. Daniels,

Los Angeles, Calif.

Application September 19, 1941, Serial No. 411,530

3 Claims.

This invention relates to an electrical system for starting and maintaining -gaseous electric discharge devices at a high power factor. Such devices, the major load of the system, may. be low gas pressure tubular lamps containing a rare gas, such as argon, and a small quantity of mercury. At the ends of the tube are the usual thermionic electrodes having leads which pass from the tube through a press or glass seal. The tube may be internally coated with fluorescent material to produce a brilliant light from a scarcely visible electric discharge. These lighting tubes are now finding general use for lighting and advertising purposes, and it is not believed necessary to completely describe these lighting tubes.

The inventive system herein disclosed is capable of maintaining a high power factor for circuits having lamps of the type recited above, and the power factor maintained as high as or better than 94%. Such lamps require a higher starting voltage than rimnlng voltage, and have negative resistance characteristics which must be high power factor obtained in this invention is maintained by utilizing much of the leakage flux invention will appear from the accompanying drawing, the subioined detailed description, the preamble oi. this specification, and the appended claims. Applicants are aboutto illustrate and describe one of the forms of their invention in order to teach one how to make, use and vend the same, but it is to be understood that the drawing and description thereof are not to limit the invention in any sense whatsoever, except as limited by the appended claims.

In the drawing: Fig. 1 of the drawing is a circuit diagram showing the invention.

' Fi 2 is a side elevation of a switch mechanism. The reference character i indicates a glass or other transparent tub or envelope for a gaseous electric discharge lamp having end electrodes or cathodes '2 and 3 which are to be. heated by elecswitch 8 is closed and opened, thereafter, the

of a regulation transformer to supply-power to the load- The manner of accomplishing this will become apparent by reading the specifications, but it is well to note that this invention materially improves the power factor of tubular lamp circuits and that the result is obtained without using large and costly condensers or transformers.

An object of our invention is to provide a simple and dependable electrical device for th starting and maintenance of gaseous electric discharge devices at a high power factor.

Another object is to-present a control unit for gaseous electric discharge devices that minimizes electrical current surges in the load devices and cause them to operate at an even steady current flow,'this result being accomplished without the aid of condensers.

A i'urther object is to provide a complete control unit for gaseous electric discharge lamps that is sturdy in electrical and mechanical construction and economical to manufacture.

Other objects, advantages and features of our cathodes are maintained at operating temperature by electronic bombardment. The switch 8 may be any type that closes when cold and opens when hot, or of the type to be later disclosed. The purpose of the switch is to place the electrodes 2 and; in series with a set of parallel running coils and a set of series booster coils when the initial starting current is applied so that the cathodes will quickly heat and be in a state to quickly emit electrons when the switch is opened, and thus rapidly. ionize the gas in the tube.

' When the cathodes of the tube ar sufficiently .heated, afterthe switch is closed, a period of a a few seconds, the switch 8 is timed to open and let the cathodes at a high voltage strike the tube; the heat of the cathodes then being maintained by electronic bombardment alone. The gaseous electric discharge switch shown in Patent #2,200,443 is a very satisfactory switch to use in this invention. A condenser 9 is shunted around the switch and provides the necessary voltage surge to start the lamp when the switch is opened.

' l3 and M. The central limb supports the primary coill5 and th side limbs the secondary coils l6 and I1, and voltage booster coils "(and I1 respectively as shown. The coils l6 and I! may be called maintenance windings for the load device and the coils 2i and 22 starting coils for purposes of identification.

The primary coil has the end leads l8 and it which connect with a source of suitable electric current at.the proper voltage through a hand switch iii. In the particular embodiment of the invention illustrated, the electric energy for the primary would be 60 cycle alternating current at about 110 volts. Obviously, the voltage would be varied to suit the demands of the load.

The secondary coil [6 has one of its ends connected to the conductor 20 which makes connection with the conductor 6, and the other end of this coil connects with the conductor through the wire 20'. The secondary coil IT has one end connected to the conductor 4 and the other end connected to the conductor 6. The core bars Ii and i2 also have the voltage booster coils 2i and 22 respectively with one of their ends connected v together by the conductor 22', one end of coil 2| having'connection with the switch through wire 5' and the other coil having one end connectedwith the conductor 7.

As an example: the load I can be a 40 watt fluorescenttube lamp which operates at a voltage of 108 and a current of 0.41 ampere; the starting voltage and cathode current being 187.5 volts and .65 amp. respectively. The line voltage is about 110 volts at 60 cycles and energizes the primary coil IS. The capacity of condenser 9 is 0.006 microfarad. Under these conditions, the coils l6 and I! should have a voltage of 140 each and the booster coils a voltage of 30 each. The dolls i6 and I1 each have 2100 turns and-the booster coils 2i and 22 each 280 turns. All cross sectional core areas should measure about x except the central limb which should be about twice the area of the other limbs.

In Fig. 2 of the drawing, a gaseous electric discharge switch is shown which is especially cameos switch 8 then opens and allows the condenser 9 to function and strike the tube at the zcovoitage. when the lamp strikes, it operates at 108 volts, the difierence between the starting and operating voltage appears in leakage reactance. A-portion of the leakage reactance is used to supply at least V2 of the 'tube's volt amperes thus this portion of leakage of flux will improve the power factor. This circuit maintains the power factor at about 94%"which is much better than the requirements of power companies.

Having thus described our invention, what is claimed as new and desired to be secured by Letters Patent is: a

1. In combination, a source of electrical power,

an electric discharge device, a switch, and a transformer unit; the unit comprising an ironcore having a central limb and two side limbs arranged to form a magnetic circuit, a primary coil on the central limb having connection with the source of power, a secondary coil set on each other limb of the transformer, each coil set having a maintenance winding and a starting winding, th maintenance windings having parallel electrical connection with each other and with the said device, the' starting windings having seadapted for use in this invention. The switch has a casing or envelop 24 which may be of glass or metal, and has the glass press or seal 25 which give support to the two bimetal strips 20 and 21, the strips having connection with the wire conductors 5 and 51 as shown in Fig. 1. One of the strips has a curled contactor 28 and ries connection with each other and with the device, and with the maintenance windings when th switch is closed, the limb having the primary coil having a cross-sectional area substantially equal to the combined areas of the other limbs havingthe coil sets, and th impedance of one secondary coil set matching the impedance of the other secondary coil set. i

2. In combination, a source of electrical power,

a transformer and a gaseous electric discharge lamp having heated cathodes; switch means in series with the cathodes to open .the circuit between them when the cathodes are heated, said transformer having a plurality of limbs forming a magnetic circuit, a central leg of the transformer having a primarywinding connected with the sourc of power, and a secondary coil set on the limbs on opposite sides of the central limb, part of said secondary coil sets and lamp hav- 1 ing parallel electrical relation and another part the other strip has a plate contactor 29. The I envelope is filled with any suitable ionizable gas such as neon. When current at proper voltage is connected across the leads 5 and 5' of the switch, an electric discharge will take place between the strips 26 .and 21 and heat them; Upon heating, the strips will flex toward each other and their ends make contact to close the circuit, contact'having been made, the switch strips 26 and 21 cool'and separate and thus open the circuit to which they are connected;

Operati n By closing the switch IS, the primary coil I5 is energized, and since the thermal switch 8 is cold and closed, or about to close when the switch shown in Fig. 2 is used, the parallel-coils l5 and 11 v.) in addition to the series booster coils 2 I and 22 (30 v. each) heat the cathodes 2 and 3 to of the coil sets having series connection with the lamp, and with said first coil parts when the switch means is closed.

3. In combination, a source of electrical power,

an electric discharge lighting device, and a netic circuit; a primary coil on one of the limbs an electron emitting temperature. The thermal transformer unit; the unit comprising an iron core having three limbs arranged to form a maghaving connection with the source of power, a secondary coil set on each of the other limbs of the transformer, each secondary coil set having a device maintenance winding connected in parallel with the device and a starting winding connected in series with the device and said maintenance windings, switch means connected between the device and transformer for closing and opening the starting winding connection with the device.

WILLARD C. HALL, Ja. 

